Control system for transportation ticket printer having plurality of dual process personal computer boards for performing general computing tasks and sending data to printer control module

ABSTRACT

An airline ticket printer includes a magnetic reading and writing station that has a read/write head for recording information on, or reproducing information from, a magnetic stripe carried on the ticket. The ticket is driven past the read/write head by a drive mechanism that contacts the ticket at a substantial distance from the read/write head so that the magnetic stripe is free to flex independently of the portion of the ticket that is in contact with the drive mechanism. More satisfactory contact between the read/write head and the magnetic stripe is thereby achieved. 
     The printer&#39;s control system includes a printer electronics board and one or more single-slot PC/AT (ISA bus) microcomputers that are plugged into respective slots of a mother board.

This application is a division of application Ser. No. 08/235,497, nowU.S. Pat. No. 5,599,117 filed Apr. 29, 1994, which is a division ofapplication Ser. No. 07/934,361, filed Aug. 25, 1992, now U.S. Pat. No.5,309,176, granted May 3, 1994.

This invention relates to printing apparatus and methods, andparticularly to apparatus and methods for printing vehiculartransportation passenger coupons such as airline tickets and the like.

Airline ticket printers are widely used to print tickets and boardingpasses, and other transportation documents for airline passengers. Onetype of airline printer is disclosed in U.S. Pat. No. 4,851,864, issuedJul. 25, 1989; U.S. Pat. No. 4,857,945, issued Aug. 15, 1989; and U.S.Pat. No. 4,962,393, issued Oct. 9, 1990. A stand-alone credit-cardoperated ticket printer of somewhat different capabilities is shown inU.S. Pat. No. 4,928,133, issued May 22, 1990. Such airline ticketprinters are highly advantageous. Nonetheless, improvements are needed.

More specifically, it is an object of the invention to improve theaccuracy and reliability of the printing apparatus for recording on andreading of information from a magnetic area or stripe on the ticket.

It also is an object of the invention to provide a printer and method inwhich the time required for printing tickets is reduced, while thenumber of different ticket stocks upon which printing may beaccomplished is increased.

Another object of the invention is to provide means for making theloading of ticket blanks into the printer easier and faster. Anotherobject of the invention is to print tickets more rapidly.

A further object of the invention is to provide such a printer andmethod in which tickets can be revised quickly and easily, and with goodsecurity.

It also is an object to provide a printer structure which simplifies andreduces the cost of its manufacture and maintenance. Further, it is anobject of the invention to provide a printer which makes maximumutilization of its electronic system.

In accordance with the present invention, the foregoing objects are metby the provision of an airline ticket printer that includes a magneticreading/writing station that has a read/write head for recordinginformation on or reproducing information from a magnetic stripe carriedon a ticket, structure for guiding tickets past the read/write head insuch a way that the magnetic stripe of the ticket is presented to theread/write head, and a drive mechanism that drives the ticket past theread/write head with the drive mechanism bearing against the ticket at asubstantial distance from the read/write head so that the magneticstripe is free to flex independently of the portion of the ticket thatis in contact with the drive mechanism. In this way more consistentcontact of the read/write head with the magnetic stripe may be achievedso as to minimize errors ("dropouts", e.g.).

A further feature of the invention is the provision of two magneticreading/writing stations in series along a ticket feed path so thaterrors in reading or writing by the first station may be detected and/orcorrected at the second station. The two magnetic stations allowmagnetic reading and writing to be performed faster and more accurately.

In accordance with another feature of the invention, assembly of theprinter is made easier by providing a sheet feeding system in the formof one or more modules that can be conveniently and precisely mounted onpins extending from a vertical mounting plate. According to a preferredembodiment of the invention, an airline ticket printer includes a printengine, a vertical, centrally located mounting plate, a plurality ofmounting pins secured to and extending perpendicular to the mountingplate, and one or more sheet feeding modules having holes shaped andsized to receive the pins, the modules being mounted on the mountingplate with the pins extending into the holes of the modules, andfasteners holding the modules onto the pins.

A further feature of the invention reduces print cycle time bypre-staging ticket blanks from a ticket storage bin to a staging point.According to a preferred embodiment of the invention, an airline ticketprinter includes a print engine, a storage bin for storing ticketblanks, a feed path for feeding the ticket blanks to the print enginefrom the bin along a guide path, and a mechanism for moving a ticketblank along the guide path to a staging point at which the ticket blankis held until a printing operation is to be performed.

According to another feature of the invention, there are also provided asecond storage bin for storing ticket blanks and a mechanism for movingblanks from the second storage bin to a separate staging point at whichthe blank from the second bin also may be held until a printingoperation is to be performed on the blank from the second bin. In thisway, print cycle times for ticket printing may be reduced whilepermitting selection of either of two kinds of ticket blanks.

Yet another feature of the invention makes it easier to load ticketblanks into the printer by providing a ticket blank storage cassette foran airline ticket printer. The cassette preferably includes ahorizontal, rectangular bottom wall having two side edges and two endedges, a pair of opposed vertical side walls extending along and risingfrom respective side edges of the bottom wall and set apart from eachother at a distance so that a stack of ticket blanks may be heldtherebetween, a first of the side walls being substantially higher thanthe other, a pair of opposed vertical end walls rising from respectiveend edges of said bottom wall and extending between the side walls, anda handle that is integrally formed with a top edge of the first sidewall and has an inverted U-shaped cross-section.

According to a further feature of a preferred embodiment, the weight ofthe ticket storage cassette is reduced, and tickets are reliably fedfrom the cassette, by providing a feed mechanism that is mounted to theticket printer. In a preferred embodiment of the invention, there isprovided in a ticket printing device, an apparatus for removing ticketsfrom a cassette which holds a stack of vertically oriented tickets, theapparatus including a structure for receiving and holding the cassette,a mechanism for upwardly feeding from the cassette a first ticket of thestack, and a bias mechanism for biasing the stack in a lateral directionso that the first ticket is engaged by the feed mechanism.

Still another feature of the invention makes it more convenient to printa new ticket when an old ticket is returned, by providing a mechanismfor inserting the old ticket into the printer, reading information thatwas magnetically encoded on the old ticket, and using the information toprint a new ticket. According to a preferred embodiment of theinvention, an airline ticket printer includes a mechanism fortransporting a ticket blank with a magnetic stripe through a firstmagnetic stripe read/write station and then to a print engine, ahousing, a mechanism within the housing for recirculating a previouslyprinted ticket through a second magnetic stripe read/write station, therecirculation mechanism including an inlet opening in the housing, aguide structure for guiding the ticket inserted through the openingtowards the second read/write station, a drive mechanism for moving theticket through the second read/write station to read the informationfrom the ticket, circuitry for receiving information read from theticket and for receiving new information and for controlling the printengine to print a new ticket using the read information and the newinformation, and a receptacle in the housing for securely holding therecirculated ticket.

Also in accordance with the invention there is provided a control systemfor an airline ticket printer which includes a mother board having aplurality of board slots, a dual microprocessor system for controllingthe printer, and formatting data to be printed, mounted on a boardplugged into one of the slots, and at least one personal computermounted on another board plugged into one of the slots, the personalcomputer being connected to send data to the dual microprocessor systemand also being adapted to perform general computing tasks.

In this way, the electric components of the printer can be used for avariety of tasks in addition to ticket printing. In a preferredembodiment, two or more personal computers are mounted in respectiveslots, so that the printer can be shared by more than one input/outputterminal.

Another feature helps to extend the life of a thermal print head used inthe printer. According to this feature, there is provided an apparatusfor printing information on a ticket that has a thickness T. Theapparatus includes a frame, a platen mounted for rotation on the frameand a print head for printing information on the ticket. There is also ameans for mounting the print head on the frame adjacent to the platen toform a gap between the platen and the print head. At least one of theplaten and the mounting means is displaceable with respect to the other.

The apparatus further includes a feed mechanism for feeding the tickettoward the gap along a feed path. A sensor is disposed in the feed pathfor sensing the feeding of the ticket and for providing a feed timesignal upon sensing the feeding of the ticket. The apparatus alsoincludes control circuitry for receiving the feed time signal and forgenerating engage signals at a timed interval after receiving the feedtime signal. Also included is an engage mechanism that includes astepper motor responsive to the engage signals, for moving at least oneof the platen and the print head in steps between a first relativeposition in which the gap is wider than the thickness T of the ticketand a second relative position in which the ticket is engaged betweenthe platen and the print head. The print head is disengaged from saidplaten except when the ticket is present between them.

According to this feature there is also provided a method of operatingan apparatus for printing information on a ticket, where the apparatusincludes a platen and a print head and the ticket has a thickness T. Themethod includes the steps of maintaining a gap between the platen andthe print head when the ticket is not present between them, the gapbeing wider than the thickness T of the ticket; feeding the tickettoward the gap; sensing the feeding of the ticket; and at a timedinterval after sensing the feeding of the ticket moving at least one ofthe platen and the print head toward the other in steps until the ticketis engaged between the platen and the print head.

This feature allows the engaging force between the platen and the printhead to be controlled more reliably than prior art systems in which asolenoid was used to engage the ticket between the print head and theplaten, thereby extending the life of the print head while maintaining adesired print quality.

It is not intended that the invention be summarized here in itsentirety. Rather, further features, aspects and advantages of theinvention will be set forth in or apparent from the followingdescription and drawings. In the drawings:

FIG. 1 is a perspective view of a portion of an airline ticket counterat an air terminal, showing several individual stations, each of whichhas one of the printers of the invention;

FIG. 2 shows an airline flight coupon printed by use of the printer andmethod of the present invention;

FIG. 3 shows a reservation/confirmation coupon printed by use of theprinter and method of the present invention;

FIG. 4 is a schematic block diagram showing the computer network towhich the individual sales terminals and printers are connected in thesale of airline tickets and other coupons;

FIG. 5 is a perspective view of the printer of the present invention;

FIG. 6 is a schematic right side elevation view of the printer of FIG. 5with its cover removed;

FIGS. 6A-6C are schematic right side elevation views of a print enginethat is part of the printer of FIG. 5;

FIG. 7 is a rear elevation view of the printer of FIG. 5 with its coverremoved;

FIG. 8 is a plan view of the printer of FIG. 5 with its cover removed;

FIG. 9 is a left side elevation view of the printer of FIG. 5 with itscover removed;

FIG. 10 is a perspective view of a ticket storage cassette used with theprinter of FIG. 5;

FIG. 11 is a cross-sectional view of the ticket cassette of FIG, 10taken along the line 11--11;

FIG. 12 is an exploded perspective view of a typical ticket feed moduleof the printer of FIG. 5;

FIG. 13 is an assembled perspective view of the ticket feed module ofFIG. 12;

FIG. 14 is a cross-sectional view of a typical feed module of theprinter of FIG. 5, showing electrical connections with printed wiringboards of the feed module;

FIG. 15A is a side view, with the cover removed, of a feed module of theprinter of FIG. 5;

FIG. 15B is a rear elevational view, with the cover removed, of the feedmodule of FIG. 15A;

FIG. 15C is a partial plan cross-sectional view of the feed module ofFIG. 15A taken along line 15C--15C of FIG. 15B;

FIGS. 16A and 16B show details of a magnetic head and pressure padassembly that make up parts of the feed module of FIG. 15A;

FIG. 17 is a block diagram that illustrates the electronic components ofthe printer of FIG. 5;

FIGS. 18A-18D are a flow chart that illustrates a procedure for printingand magnetically recording information on tickets by use of the printerof FIG. 5;

FIG. 19 is a flow chart that illustrates a procedure for recirculatingan old ticket into the printer of FIG. 5 and using the printer to printa new ticket.

GENERAL DESCRIPTION

FIG. 1 shows a typical airline ticket selling counter 30 with individualticket selling stations shown at 32, 34, and 36. At each station thereis a counter top 38, an input/output device 40, a relatively lowbaggage-receiving and weighing surface 42, and a coupon printer 44.Printed tickets or other coupons are issued through an outlet opening 48in the front of the printer. Each input/output device has a video screenand a keyboard enabling the operator to input passenger and otherinformation and retrieve information regarding seat availability, etc.

As it is shown in FIG. 4, each input/output device 40 is connected bymodems and other equipment (not shown) through remote links 80 to acentral computer system 82 in a regional or nationwide network involvinga plurality of different input/output stations at locations 72, 74, 76,78 etc.

If desired, each location can contain as few as one input/output device40 and one printer 44, as in the case of the location 72, which might bea travel agent's office, for example, or it can contain a large numberof such combinations as in an airline terminal 78. The computer system82, an example of which is called "Apollo", computes, stores and sendsreservation data and other data necessary to enable the ticket salespersonnel to sell tickets, and to enable the printers to print coupons.

Referring again to FIG. 1, the printers 44 are fitted into relativelynarrow and restricted cabinet spaces in the counters. The printers areconstructed to roll outwardly from the cabinets so as to give theoperator ready access to the printer mechanism. The printer 44 shown inthe lower right hand portion of FIG. 1 has been withdrawn from itscabinet in the manner described. Preferably, a key must be inserted intoa lock (not shown in FIG. 1) on the front of the unit to release it fromthe cabinet so it that can be pulled out. This lock preferably disableshigh voltage circuitry within the printer mechanism so as to allowoperators to handle it without being shocked.

FIGS. 2 and 3 show two different types of coupons which can be printedby the printer mechanism 44 for use in airline transportationtransactions.

FIG. 2 shows a passenger ticket and baggage check form 50. The form 50has a stub end portion 52 which is intended for use in stapling theforms together and thus is excluded from the area to be printed on. Theportion 52 is separable from the body of the form by perforations at 54.The form also has a boarding pass portion 56 at the opposite end. Theboarding pass 56 is easily separable from the remainder of the coupon bymeans of a perforation 58.

The form 50 includes spaces for printing all relevant passengerticketing information, including the amount of the fare and the totalcost. It also includes a space for printing baggage information so thatthe coupon can be used by the passenger to reclaim his or her baggage.

Each of the forms 50 includes a pre-printed serial number indicated at64. The forms are numbered serially so that strict accounting can be hadfor all forms issued. Each ticket agent or travel agent is held strictlyaccountable for every form issued to him or her. For example, during theshift of a ticket agent at one of the ticket counters shown in FIG. 1,the agent will be issued a group of serially-numbered forms, and theagent must account for all of those forms at the end of his or hershift. Thus, there is a significant need for the printer to avoid losingor damaging forms in the printing process. Furthermore, if two forms arefed simultaneously or a jam occurs, the operator should correct thesituation immediately, in order to avoid the loss of a form. The printershould not require the operator to destroy forms in the process.

Still referring to FIG. 2, on the rear surface of the form 50 is amagnetic stripe 62 shown in dashed lines extending the entire length ofthe form near its upper edge as shown in FIG. 2. Data regarding thepassenger and the transaction are recorded on the magnetic stripe 62 andcan be read by magnetic reading means to input the data quickly into thecentral computer for use in its operations, or for a variety of otherpurposes.

The coupon 66 shown in FIG. 3 is a reservation confirmation coupon orform for automobile rentals made by the passenger through a travel agentor airline ticket agent. The form 66 is not perforated.

Reservation confirmation form 66 also can be used for confirming hotelreservations or any similar matter to be handled by the ticket agent ortravel agent. Both types of travel coupons 50 and 66 shown in FIGS. 2and 3 can be stored in and printed by the printer 44 upon demand. Otherforms having the same size and shape as coupons 50 and 66, such asairplane boarding pass blanks, can also be used with printer 44.

Referring now to FIG. 5, printer 44 includes a cabinet 100 with a frontpanel 102, which includes an inclined upper portion 104. Upper portion104 has a display section 106 and a key pad 108. Display section 106 mayinclude, for example, an LED display and/or LCD display.

Upper portion 104 also has a recess 110 in which are located outletopening 48 and inlet opening 112. Cabinet 100 is mounted on casters 114(FIGS. 6 and 9) which allow printer 44 to be rolled in and out of ticketcounter 30, as discussed above.

Ticket Feed Paths

Referring now to FIG. 6, there will now be described in general termsfeed paths for tickets within printer 44. Held within cabinet 100 areremovable ticket blank supply cassettes 130 and 132. As shown in FIG. 6,cassette 132 holds a plurality of ticket forms 50 and cassette 130 holdsa plurality of reservation forms 66. It will be appreciated that it ispossible to store identical ticket blanks in both cassettes 130, 132 ifonly one type of blank is required. Blanks 50 and 66 are held in asubstantially vertical orientation within cassettes 132 and 130.

As schematically shown in FIG. 6, blanks may be withdrawn from eithercassette 130 or cassette 132 and advanced to respective staging points134 and 135, at which the blanks are held until a printing operation isinitiated, as will be discussed in more detail below. A ticket blankfrom cassette 130 and a ticket blank from 132 may be simultaneously heldat staging points 135 and 134 respectively.

From the staging points a feed path 136 is defined which leads to printengine 138. Located along feed path 136 is a magnetic read/write station140 at which data may be recorded on, or reproduced from, a magneticstripe 62 of a ticket blank.

A feed path 142 leads from inlet opening 112. A magnetic read/writestation 144 is located along feed path 142.

It will be observed that feed path 144 initially proceeds rearwardlyfrom inlet opening 112 and then downwardly and forwardly while firstfeed path 136 extends upwardly from staging point 134 and than forwardlyand downwardly. The two feed paths 136 and 142 converge to form a commonfeed path section 146 which leads on to print engine 138. Located alongfeed path section 146 is a magnetic read/write station 148.

The feed paths are constructed with feed modules 150, 152 and 154, whichwill be described in more detail below.

After passing through print engine 138, tickets may be either fed out tooutlet opening 48 or through stacker door 156 or diverted to secureholding bin 158.

Check Valve

As will be discussed below with respect to FIGS. 18A-18D, if an erroroccurs in magnetic recording or reading of information on a ticket 50,the ticket may be reversed along feed path section 146 so that it may beadvanced a second time past magnetic read/write station 148. Moreover,in a high speed mode of operating printer 44, tickets may be fed inrather close proximity to each other so as to achieve a time betweentickets of approximately 0.463 seconds. In such a high speed mode, afirst ticket may be advanced past magnetic read/write station 148 at thesame time that a second ticket is advanced past magnetic read/writestation 140. In that case, if there is an error in reading or recordinginformation on the first ticket, it may be desired to run the feedingmechanism of feed module 152 in reverse so that reading of or recordingon the first ticket may be reattempted. In order to prevent the secondticket (i.e. the one near station 140) from being fed back into stagingpoints 134 and 135 and causing Jams therein, feed module 152 is providedwith a check valve 160 at its inlet 159. Check valve 160 includes agravity gate member 161 that is mounted on a pivot 162. Gate member 161freely rotates upward (i.e. clockwise, as seen in FIG. 6) from itsposition shown in FIG. 6 so that blanks fed from staging points 134 and135 may freely advance into inlet 159 of feed module 152. However, gatemember 161 is prevented from rotating downward (i.e. counter-clockwise)beyond the position shown in FIG. 6, so that when a second ticket isreversed past station 140, the second ticket is diverted by gate member161 into a temporary holding area 163. When the first ticket is advancedagain past station 148, the second ticket will be simultaneouslyadvanced from holding area 163 past station 140.

Print Engine

Print engine 138 includes a platen 164 and a thermal transfer unit 165which cooperates with platen 164 to transfer characters and otherprinted images from a thermal printing ribbon 166 onto tickets 50 thatare fed in between platen 164 and transfer unit 165. Ribbon 166 isunwound from supply reel 168 and is taken up by take-up reel 167.

Details of print engine 138 are shown in FIGS. 6A-6C.

Thermal transfer unit 165 includes a print head 400 which is mounted onhead carrier bar 402. Carrier bar 402 is mounted on pivot 404 forpivotal motion in a generally upward or downward direction. Also mountedon pivot 404 is spring keeper 406 which extends longitudinally above andgenerally parallel to the top surface of carrier bar 402. Spring keeper406 is pivotable for movement in a generally upward or downwarddirection. Pivot 404 is mounted to a fixed structure of printer 44, suchas frame 399 (FIGS. 6B, 6C).

A distal end 408 of spring keeper 406 rests upon a compression spring410 (FIG. 6A) and serves to retain compression spring 410 in a recess412 that is formed in the upper surface of head carrier bar 402.

Also mounted on pivot 404 is torsion spring 414. Spring 414 has legs 416and 418. Leg 416 contacts a pin 420 that is mounted on the frame 399 ofprinter 44, while leg 418 contacts pin 422 that is mounted on carrierbar 402. Spring 414 is arranged to bias carrier bar 402 in an upward(i.e. clockwise) direction.

A head return stop pin 424 is mounted on the frame 399 of printer 44above head carrier bar 402 and provides back-up or overrun protection tolimit the upward motion of carrier 402.

A rocker arm 426 is pivotally mounted on the frame 399. Rocker arm 426has tangs 428 and 430 which extend tangentially from rocker arm 426 atsubstantially a right angle from each other. Tang 428 extends in agenerally horizontal direction and contacts the upper surface of end 408of spring keeper 406.

Tang 430 extends in a generally upward direction. A spring 432 connectedbetween the frame 399 of printer 44 and tang 430 biases rocker arm 426in a counterclockwise direction (FIG. 6A). Stop pins 434 and 436 arerespectively mounted to the left and right of tang 430. Pin 434 limitsthe movement of tang 430 and rocker arm 426 in the counterclockwisedirection and pin 436 limits the movement of tang 430 and rocker arm 426in the clockwise direction.

Referring to FIG. 6B, rocker arm 426 has a pulley 438 mounted thereto.Pulley 438 is connected via belt 440 to a head engagement stepper motor442.

Located to the right of platen 164 is drive roller 444. Idler roller 446is paired with drive roller 444.

Referring to FIG. 6C, a common drive belt 447 allows both platen 164 anddrive roller 44 to be driven in a counterclockwise direction by a carddrive stepper motor 448.

As best seen in FIGS. 6A and 6C, a sensor 450 is disposed between platen164 and roller 444. Sensor 450 has a pivotally displaceable flag 452that extends upwardly into a card feed path (indicated by arrows 454)between the nip of rollers 444 and 446 and toward a gap 456 that isformed between platen 164 and print head 400. A sensor 458 is located tothe left of platen 164. Sensor 458 has a pivotally displaceable flag 460which extends generally downward into card exit path 462.

In a preferred embodiment of printer 44, sensor 450 and 458 are of atype in which displacement of their respective flags to the positionsshown in phantom on FIG. 6A, breaks an optical connection that ismaintained when the respective flags are in their normal positions, asshown by solid lines, particularly in FIG. 6A.

There will now be described operation of print head 400 for engagementand disengagement. Rocker arm 426 is normally held in its home position(shown in solid lines) by the biasing force of spring 432, and with tang430 in contact with stop pin 434.

When rocker arm 426 is in its home position, the biasing force of spring414 holds carrier bar 402 in such a position (the "disengaged" position)that head 400 is spaced apart from platen 164 by a gap distance ofapproximately 0.010 to 0.015 in. As is well known to those skilled inthe art, a typical card to be printed has a thickness T of about 0.007in, so that the gap 456 between platen 164 and head 400 is wider thanthe thickness T of the ticket when head 400 is in the disengagedposition. The upward movement of head carrier bar 402 is limited by tang428 of rocker 426, which acts on carrier bar 402 through spring keeper406 and compression spring 410. In a preferred embodiment of printer 44,pin 424 is also present as overrun protection to stop upward movement ofhead carrier bar 402.

When a ticket blank is driven by rollers 444 and 446 toward platen 164,the leading edge of the ticket displaces flag 452, tripping sensor 450.Sensor 450 is connected (connections not shown) to print engine control(PEC) electronics, which are described below, and provides a feed timesignal to PEC electronics. After a predetermined period after receipt ofthe feed time signal and under software control, head engagement motor442 is driven, as described just below, to move head 400 downwardly sothat the ticket is engaged between head 400 and platen 164. Preferablyengagement occurs when the leading edge of the ticket has progressedthrough the head/platen gap 456 to the extent of 0.05 in.

Engagement of a ticket between head 400 and platen 164 will now bedescribed. At a timed interval after receipt of the feed time signal,the PEC supplies engage driving signals (i.e. pulse signals) to steppermotor 442 (for simplicity, the connection between motor 442 and the PECis not shown). Under control of pulses received from the PEC, steppermotor 442 rotates in steps in a clockwise direction E (FIG. 6B) causingrocker arm 426 to be rotated clockwise. Tang 428 of rocker arm 426 isrotated a few degrees downwardly, thereby pressing on spring keeper 406(FIG. 6A), which in turn compresses spring 410. Spring 410 then moveshead carrier bar 402 downwardly in steps against the biasing force ofspring 414, so that the ticket is engaged between head 400 and platen164. It will therefore be appreciated that spring 410 transmits adownward force from rocker arm 426 to carrier bar 402.

In a preferred embodiment, rocker arm 426 is driven by motor 442 so thatin its engaged position (shown in phantom), tang 430 is a short distanceto the left of stop pin 436. Stop pin 436 thus functions as an overrunprotection pin so that an excessive force is not applied to head 400.The printer control electronics are programmable to reduce the distancebetween the engaged position of tang 430 and pin 436 if it is desired toadjust print quality by arranging tighter engagement of the ticketbetween head 400 and platen 164. Stepper motor 442 is a high torque, lowinertia motor so that in the event of a power outage, the force ofspring 414 will be sufficient to rotate carrier bar 402 upwardly (andthereby rotate rocker 426 in a counterclockwise direction) so that head400 is disengaged from platen 164.

Printing upon the ticket is carried out in accordance with the timing ofthe detection of the ticket by sensor 450. When printing is complete andthe ticket has been advanced so far that the trailing edge of the ticketis approximately 0.05 in. from exiting gap 456, motor 442 is pulsed torotate in the counterclockwise direction so that rocker arm 426 alsorotates counterclockwise. The pressure of tang 428 on spring keeper 406is thereby lessened, allowing carrier bar 402 to move upwardly(clockwise) under the force of spring 414, so that head 400 isdisengaged from the ticket and platen 164, and rocker arm 426 and springkeeper 406 return to their home positions. It will be understood thatthe ticket continues onward along path 462 to exit the printer 44, withplaten 164 acting as an exit roller. Sensor 460 is provided to detectwhether the ticket has for some reason failed to properly exit printer44, e.g. because of a jam.

It will be understood from the foregoing that head 400 is disengagedfrom platen 164 at all times except when a ticket is interposedtherebetween. By preventing direct contact between head 400 and platen164 the life of the print head is extended by minimizing abrasion and byassuring that the ticket is available for diffusion of heat produced byhead 400.

In a preferred embodiment of printer 44, tickets are driven within feedmodule 152 at a rate of 21 inches per second, for rapid feeding oftickets from cassettes 130 and 132 to print engine 138. Feeding withinprint engine 138 (i.e. by rollers 444 and 446 and platen 164) is therate of 4 inches per second. Accordingly, roller 444 is driven with aone way clutch, so that when a ticket is fed from module 152 to the nipof rollers 444 and 446, roller 444 is free to be accelerated by theticket to allow the ticket to continue to advance at the rate of 21inches per second. At a point where the leading edge of the ticket isapproximately 1/4 inch from flag 452 of sensor 450 the trailing edge ofthe ticket is ejected from the nip of the last feed roller of module 152and is immediately decelerated by roller 444 and 446 so that the ticketis thenceforward driven at a rate of 4 inches per second through theaction of rollers 444 and 446, platen 164 and ticket drive motor 448.

Although in the embodiment shown in FIGS. 6A-6C, platen 164 is rotatableabout a fixed axis, with head 400 being mounted for movement betweenretracted and engaged positions, it will be appreciated that alternativeembodiments are possible in which head 400 is fixedly mounted and platen164 is retractable therefrom. It will also be appreciated that bothplaten 162 and head 400 may be mounted for retracting movement withrespect to each other.

It will be appreciated that other types of printing mechanisms, such asa direct thermal print engine or an ion deposition engine, may be usedinstead of the thermal transfer print engine 138 shown in FIG. 6.

Internal Structure

The overall internal structure of printer 44 will now be described withreference to FIGS. 7-9. Vertical mounting plate 180 runs longitudinallynear the center of cabinet 100 and is mounted on base 182 which formsthe floor of cabinet 100. Plate 180 is rigid and substantial andsupports many of the mechanical and electrical components of printer 44.Plate 180 may support frame 399 (FIGS. 6B, 6C) or may integrally includeframe 399.

A plurality of mounting pins 184 extend perpendicularly from mountingplate 80, as best seen in FIG. 7. Feed modules 150, 152 and 154 aresecured to mounting plate 80 by pins 184. Ticket cassettes 130 and 132are placed adjacent to plate 180 and below module 150. Passing throughplate 180 are sockets 188 which permit interconnections betweenelectronic components of the tape modules and the electronic controlcomponents of printer 44 which are located on the opposite side of plate180.

Among the electrical and electronic components are power-supply 190,PC/AT card 192 and printer electronics board 194. Both PC/AT card 192and printer electronics board 194 are received within slots 195 ofmother board 196. Empty slots 195 may be used to accommodate optionalelectronics modules such as additional PC/AT cards, communications andLAN cards, a fax card, a video card, memory expansion cards, and thelike.

PC/AT card 192 controls floppy disk drive 198, to which it is connectedthrough mother board 196.

Power supply 190 is located in the upper part of cabinet 100 to aid indissipation of heat produced by power supply 190.

Structure of Ticket Cassettes

The structure of ticket cassette 132 (which is identical to cassette130) will now be described with reference to FIGS. 10 and 11.

Ticket cassette 132 is preferably constructed of a thin walled material,such as metal or plastic, and includes a horizontal, rectangular bottomwall 202 which has relatively long side edges 203 and 204 and relativelyshort end edges 205 (FIG. 10) and 206 (FIG. 7).

A relatively low rectangular side wall 207 extends along and rises fromside edge 204 of bottom wall 202. Located opposite to wall 207 is arelatively high vertical side wall 208 which extends along and risesfrom side edge 203 of bottom wall 202. Vertical end wall 209 issubstantially L-shaped and rises from end edge 205 of bottom wall 202.End wall 209 extends between side walls 207 and 208. As shown in FIG. 7,a second vertical end wall 210 rises from end edge 206 of bottom wall202. End wall 210 also extends between side walls 207 and 208. End wall210 is cut at an angle so that its height varies from that of side wall208 to that of side wall 207. Referring again to FIGS. 10 and 11, ahandle 211 is formed integrally with the upper edge of high side wall208 and has a cross section that is an inverted U-shape.

A stack of ticket blanks 50, including a first ticket blank 50-1 and alast ticket blank 50-L, is held between opposed side walls 207 and 208and is supported by bottom wall 202. As previously noted, the stack ofticket blanks is held in a vertical orientation. Ticket blank 50-1 isheld adjacent to end wall 210.

In a preferred embodiment of cassette 132, bottom wall 202 is 33/8 in.wide (i.e. end edges 205 and 206 are 33/8 in. long) so as to ratherclosely accommodate a vertical stack of standard tickets blanks that are31/4 by 8 in. In that embodiment, bottom wall 202 is 8 in. long, sidewall 208 is 61/2 in. high and side wall 207 is 11/4 in. high.

Referring again to FIG. 6, a tray 212 is fixed to the bottom of cabinet100. Tray 212 includes two slots 213 and 214, each of which is sized toreceive a respective one of cassettes 130 and 132. Slots 213 and 214respectively receive and hold cassettes 130 and 132.

Bias means 215 and 216 are both mounted on plate 180. Mounted on eachbias means is a push plate 217. A spring, such as a constant forcespring, or another biasing mechanism biases push plate 217 so that itexerts a force (represented by Arrow F in FIG. 10) on the last ticket50-L of the stack of tickets held in a respective ticket cassette 130 or132. Push plate 217 is accommodated by the L-shape of end wall 209 sothat it is in contract with ticket 50-L. Thus, each push plate 217biases a respective stack of ticket blanks in a lateral direction. Thefirst ticket 50-1 of each stack is brought into engagement with a feedmeans such as a feed roller 218. In cooperation with the force exertedby its respective push plate 217, each feed roller 218 upwardly feedsthe first ticket so that it is removed from its ticket cassette and isfed into feed module 150.

Feed Module Structure

As shown in FIGS. 12 and 13, a typical section of a feed module includesframe halves 220 and 222.

Frame halves 220 and 222 respectively include module walls 224 and 226.Extending respectively from walls 224 and 226 are guide halves 228 and230. Formed in each guide half is an aperture break 232.

Frame halves 220 and 222 also include assembly bosses 234 and PWB slots236. Frame halves 220 and 222 further include mounting holes 238 thatare sized to receive a mounting pin 184. Frame halves 220 and 222 alsohave holes 240 for receiving stepped shafts 242 on which are mountedrollers 244.

The module is assembled by aligning corresponding assembly bosses of theframe halves 220 and 222 and bringing the bosses into abutment. Shafts242 are held between the frame half 220 and 222 by holes 240. It will beseen that four rollers 244 form an upper and lower pair of rollers andthat the upper pair carries an endless driving belt 246.

Guide halves 228 and 230 join to form document guide 248 and PWB slots236 also Join to form a slot for holding a printed wiring board.Further, aperture breaks 232 of the respective guide halves join to forma driving aperture 250, through which belt 246 engages lower rollers 244in order to drive a ticket blank 50.

The module is mounted to mounting plate 180 with a mounting pin 184passing through respective holes 238 of frame halves 220 and 222. Clip252 includes a slot 254 which engages pin 184 and allows clip 252 to beinserted into a circumferential locating groove 256 of pin 184 to securethe module to plate 180.

FIG. 14 shows a typical interconnection of printed wiring boards forfeed modules. A PWB backplane 280 is connected to a socket 188 inmounting plate 180.

Socket 188 is preferably a 48-pin or 96-pin socket of a known type andis connected via conventional flex circuits (not shown) to electriccomponents of printer 44 located to the left of plate 180 (thoseelectric components are not shown in FIG. 14; see FIGS. 7-9).

Referring again to FIG. 14, a host printed wiring board 282 and a slaveprinted wiring board 284 are both connected to backplane 280.

Magnetic Read/Write Stations

Details of the magnetic read/write stations will now be discussed withreference to FIGS. 15A, 15B and 15C.

FIG. 15A is a side elevation view of feed module 152 with its outermodule wall removed. Module 152 includes magnetic read/write stations140 and 148. Each station 140 and 148 includes a driving belt 246carried on a first pair of rollers 244. A biasing means such as springs300 urges belt 246 and its rollers 244 towards a second pair of rollers244 so that belt 246 engages the second pair of rollers in order todrive ticket blanks 50.

Rollers 244 and driving belt 246 are disposed substantially in thecenter of the width of document guide 248 so as to engage ticket blanks50 in an area A (FIG. 2) which is substantially in the center of thewidth of ticket blank 50.

Each magnetic read/write station also includes a magnetic head 302 and apressure pad 304. As best seen in FIGS. 16A and 16B, pressure pad 304 ismounted to pivot arm 306 which in turn is mounted on module wall 226 bymeans of pivot 308. Spring 310 biases pivot arm 306 so that it pivots tourge the pressure pad 304 into contact with magnetic head 302. Themounting of pressure pad 304 on pivot arm 306 is via gimbal pin 311.Pressure pad is fixedly mounted around pin 311, but an end of pin 311 issomewhat loosely mounted in pivot arm 306 allowing pad 304 a few degreesof movement in any direction. This arrangement effectively gimbals thepressure pad 304, so that it provides compliance to magnetic head 302and ticket blanks 50 in more than one direction. Thus when a ticketblank 50 is driven through a magnetic read/write station, pressure pad304 contacts the face of ticket blank 50 urging magnetic stripe 62carried on the back of ticket blank 50 into contact with magnetic head302 for recording of information on or reproducing of information frommagnetic stripe 62.

Referring again to FIGS. 15B and 15C and to FIG. 2, it will be observedthat magnetic head 302 and pressure pad 304 are offset a distance Dalong the width of document guide 248 from rollers 244 and drive belt246. This distance D is sufficiently large so that the portion of ticketblank 50 bearing stripe 62 is free to flex independently from theportion of ticket blank 50 that is in contact with belt 246 and itsopposed rollers 244. Pressure pad 304 is therefore able to act on ticketblank 50 so as to achieve satisfactory contact of magnetic strip 62 withmagnetic head 302.

Feed module 152 includes a motor 312 for driving the various ticketfeeding elements of module 152. Driving connections between motor 312and the ticket feeding elements are not shown.

Module 152 also has a number of sensors 314, arranged at appropriatelocations along feed path 136, for sensing the presence of a ticket 50at the respective location. Connections for carrying signals betweensensors 314 and electric components such as PWBs 282 and 284 are notshown.

As will be understood by those skilled in the art, feed modules 150 and154, which are shown schematically in FIG. 6, have drive motors, ticketfeeding elements such as pairs of opposed rollers or drive belts withopposed rollers, driving connections between the motors and the feedingelements, ticket position sensors, and so forth. For the most part,these elements are not shown in FIG. 6.

Electronic Components

The electronic components of printer 44 will now be described in moredetail, with reference to FIGS. 7 and 17.

As previously mentioned with respect to FIG. 7, printer 44 includes amother board 196 which has a plurality of slots (for example, fiveslots). Slots 195 will accept PC/AT compatible printed circuit boards.Mother board 196 is arranged to provide interconnections among boardsinstalled in slots 195, and between such boards and the feed modules,the print engine and other components of printer 44. Mother board 196also includes non-volatile memory which may, for example, comprise 2 Kbytes of static RAM backed up with a lithium battery. As shown in FIGS.7 and 17 a PC/AT card 192 and a printer electronics board 194 areinstalled in respective slots 195. Installed in another slot 195 is aspecial purpose peripheral card 340 such as a fax card, a LAN card orWAN card. Card 340 is compatible with the PC/AT standard bus (known asan "ISA" bus).

PC/AT card 192 may be specially designed for multi-microcomputer use, ormay be a conventional 386SX PC/AT plug-in card that includes an Intel80386SX microprocessor, an Intel 80387SX numeric coprocessor, 8megabytes of DRAM, a BIOS EPROM, battery-backed-up 32 K×8 SRAM, anexpansion card with VGA and two RS-232 ports, a PC/AT chip set such asthat (such as that available from VLSI Technology known as the "Scamp"0chip set that includes a model VL82C311 system controller bus controllerchip, a model VL82C106 combo interface chip that includes two VL16C450UARTS), a parallel printer interface, a keyboard/mouse controller and areal time clock, a model WD37C65C floppy disk subsystem controller chip(available from Western Digital), and suitable bus connections betweencomponents of the PC/AT card.

If PC/AT card 192 is of the specially-designed type mentioned above, itmay also include a bus-tie strap/connector 341 to eliminate buscontention when multiple microcomputer boards are in use on the samephysical bus. This bus-tie strap/connector arrangement also accommodatesa daughter board 339, which contains an optional VGA video subsystem andtwo additional serial ports. The daughter board 339 permits a completePC/AT type microcomputer to fit into a single card slot 195, so thatother slots are not required for video or additional serial ports.

PC/AT card 192 is connected to a terminal 40, which includes a display342 and keyboard 346. Appropriate cabling connects keyboard 346 to PC/ATcard 192, and another cable connects display 342 to daughter board 339.Terminal 40 may be used to control operation of, and exchange data with,printer 44.

PC/AT card 192 may also connected to a page printer 343, which itcontrols. PC/AT card 192 is also connected to, and controls, floppy diskdrive 198 and a hard disk drive 344. One or more additional PC/AT cards192' and terminals 40' (shown in phantom in FIG. 17) may be connected toprinter 44 via remaining slots 195, so that a single printer 44 caneasily be shared by several terminals 40.

As shown in FIG. 17, printer electronics board 194 includes an executiveprocessor (EP) section 350, a print engine control (PEC) section 352 anda print engine control I/O (PEC I/O) section 354.

EP 350 has a bi-directional data path connection via mother board 196with PC/AT card 192, and serves as a communication link between printer44 and PC/AT card 192. EP 350 preferably includes an Intel 80188processor, 128 K bytes of EPROM and 128 K bytes of DRAM with hardwarerefresh. At least some non-volatile memory located on mother board 196is addressable by EP 350, for internal storage of configurationparameters and error information.

PEC 352 preferably includes an Intel 80188 processor, 1 Mbyte of DRAMand a 64K ROM (or EPROM) for storing executable code, fonts and graphicimages. PEC I/O 354 handles interchange of data between EP 350 and PEC352. Additional executable code fonts and graphics may be downloaded forstorage and use in PEC 352.

PEC 352 is connected to print engine 138 and controls the print head ofprint engine 138 to print graphics and bit mapped pixel imagescorresponding to data (in ASCII form, for example) received from EP 350.

Executive processor 350 is connected to serial party-line bus (PLB) 356which is preferably a Phillips I² C bus. Executive processor 350 isconnected through PLB 356 to the following the electronic components ofprinter 44: reinsert control electronics module 358; magnetic read/writecontrol module 359; ticket movement electronics module 360; front panelelectronics module 362; and drum motor controller 364.

Magnetic read/write control module 359 includes a Phillips 8XC552microcontroller connected to an internal ROM and an external RAM. Themicrocontroller is in communication with EP 350 via PLB 356 and controlsread and write operations of magnetic heads 302 of stations 140, 144 and148.

Ticket movement module 360 includes a Phillips 8XC552 microcontrollerwith an internal ROM and RAM. This microcontroller controls all thedrive motors for ticket feeding, including motors for picking ticketsfrom cassettes 130 and 132. The same controller also receives signalsfrom the various sensors that sense the presence of cassettes 130 and132 or that sense presence of tickets in, or passage of tickets through,various parts of the ticket feed paths. This controller also is incommunication with EP 350 via PLB 356.

Reinsert control module 358 is identical to module 360 in terms ofhardware, but preferably has stored control software that is somewhatdifferent from module 360's software.

Front panel electronics module 362 handles the input and output devicescontained in the upper portion 104 of printer 44's front panel. Module362 controls a solenoid that causes diversion of tickets to escrow bin158 and also receives signals from sensors that indicate whether ticketshave been properly ejected from printer 44 and whether the escrow bin158 or an external storage bin (not shown) is full. (Use of an externalstorage bin with a ticket printer is well known and is described in U.S.Pat. No. 4,962,393, cited above.) Module 362 also receives signals thatindicate whether doors of cabinet 100 are closed and locked, whether anexternal storage bin is present and plugged into printer 44 and whetherthere is a ticket jam at an exit point from printer 44. Module 362 alsocontrols motors for ejecting tickets from printer 44.

Module 362 is in communication via PLB 356 with EP 350 and preferablyincludes a microcontroller of the 8051 family.

Module 362 is connected to a socket 363 (see also FIG. 5) through whichexternal devices may be directly connected to PLB 356. Module 362 isalso adapted to be connected to the electronics module of an externalstorage bin (not shown).

Drum motor controller 364 includes a microprocessor that communicateswith EP 350 over PLB 356. Controller 364 is connected to print engine138 and receives encoder signals that indicate the speed of the drummotor of print engine 138. Controller 364 is suitably connected tocontrol the drum motor's speed and is also interfaced to a heater (if athermal print engine is used) so as to control the drum temperature.

EP 350 is also connected by PLB 356 to control diagnostic circuitry ofprint engine 138.

While printer 44 is operable with only a single PC/AT card 192 installedin one of slots 195 to act as a front-end and console processor forprinter 44, the specially-designed card 192 described above is such thatseveral cards 192 may be installed in slots 195 for connection to astandard PC/AT (ISA) bus for independent and concurrent operation.

An important part of the design of the specially-designed cards 192 isthe above-mentioned bus-tie strap 341 which allows cards 192 to beconnected to the bus as masters controlling peripheral cards pluggedinto the bus. The bus-tie strap can be removed from a card 192,permitting the card 192 to operate independently and simultaneously withother cards connected to the bus without interference or contention.

In a preferred mode of operating printer 44, one PC/AT card 192installed in a slot 195 serves as a system front-end or "master"processor, and has its bus-tie strap in place. Master PC/AT card 192communicates with EP 350 through the ISA bus to control printer datastreams and functions. (It will be understood that EP 350 is interfacedto the bus as an ISA peripheral board.) Master PC/AT card 192 alsoexchanges data with other peripheral cards for receiving host data,accessing disk drives, etc.

Other PC/AT cards 192 are installed in respective slots 195 but havetheir bus-tie straps removed to allow them to operate independently forproviding console and PC functions to additional users. Each of theother cards 192 communicates with master PC/AT card 192 via RS232 serialports, with the master PC/AT card 192 concentrating print data streams,buffering the data, and metering the data out to EP 350.

Preferably each card 192 has non-volatile (e.g. battery-backed-up) RAMon-board, for the purpose of preserving host data between the time itwas received and the time of printing. In the event of a power outage,the data stream is thus preserved for resumption of printing when poweris restored. This permits complete accounting for ticket blanks 50,which as noted before are to be strictly controlled.

Magnetic Read/Write Operations

Reading of information from, and writing of information upon, magneticstripes 62 of ticket blanks 50 will now be described with reference toFIGS. 18A-18D.

Upon commencing a form feeding operation, it is first determined (step1000) whether ticket blanks have been pre-staged to staging points 134and 135. If not, a ticket blank is pre-staged to each staging point atwhich a ticket blank is not present (step 1002).

Following step 1002, or directly following step 1000, as the case maybe, is step 1004, at which it is determined whether the form to be fedis one of the type stored in the primary bin (i.e. cassette 132). Ifnot, a ticket blank is fed from staging point 135 (step 1006).Otherwise, a ticket blank is fed from staging point 134 (step 1008).

Following either step 1006 or step 1008, as the case may be, is step1010, at which it is determined whether a stock control number (SCN) orother pre-encoded information is to be read from the ticket blank. Ifso, step 1012 follows at which the SCN or other information is read atthe first read/write station (i.e. station 140). Following step 1012 isstep 1014 at which it is determined whether the sensor (not shown) forthe appropriate staging point is clear. In other words, a test is madeto determine whether proper feeding to station 140 occurred. If not, analarm is sounded (step 1016) and the feed routine ends to permit jamclearance, etc.

If the sensor was found to be clear at step 1014, then step 1018follows, at which a blank from the appropriate cassette 130 or 132, asthe case may be, is fed to the staging point from which a ticket blankhas just been fed to station 140.

After step 1018 is step 1020, at which it is determined whether thereading of the SCN was successfully performed. If not, step 1021follows, in which an alarm is sounded and the ticket is fed into escrowbin 158. The routine then ends. Alternately, at step 1021 the ticket maybe fed to print engine 138 where "VOID" or a similar marking is printedon the ticket.

If at step 1020 it is found that the SCN was successfully read, step1022 follows step 1020. At step 1022 it is determined whetherinformation is to be written into the magnetic stripe 62 of the ticketblank which has just been read at read/write station 140. If so, theinformation is encoded and verified at the second station, i.e. station148 (step 1024).

Following step 1024 is step 1026, at which it is determined whether theencoding of information successfully occurred at step 1024. If not, step1028 follows, at which it is determined whether this was the thirdattempt to write information into the current ticket form. If so, analarm is sounded (step 1030) and the routine ends to permit remedialaction by the operator. Otherwise, step 1032 follows step 1028. At step1032 the current ticket form is fed-backward and then passed againthrough station 148 in another attempt to record the information intomagnetic stripe 62 (step 1034). Following step 1034, the routine returnsagain to step 1026 to determine whether the additional attempt wassuccessful.

Again considering step 1026, if successful writing of information isfound at that step, the routine proceeds to step 1036, at which the cardis advanced through the feed path to print engine 138 and information isprinted on the ticket form.

From step 1036 the routine proceeds to step 1038 at which it isdetermined whether the ticket just printed is the last one to be fed. Ifso, the feed routine ends. Otherwise, the routine proceeds to step 1040to initiate an additional ticket form feed and print cycle. Thus afterstep 1040 the routine proceeds to step 1004 as previously described.

Returning again to consideration of step 1010, if at that step it wasdetermined that SCN or other information was not to be read from thecurrent ticket form, then the routine proceeds from step 1010 to step1042, at which it is determined whether data is to be written intomagnetic stripe 62 of the current ticket form. If not, the routineproceeds to step 1036, which was described above. Otherwise, the routineproceeds to step 1044, at which information is written by read/writestation 140 onto magnetic stripe 62 of the current card.

Following step 1044 is step 1046, at which it is determined whether thestaging point from which the ticket has just been fed is clear. If not,an alarm is sounded (step 1048) and the feed routine ends to permit jamclearance, etc. Otherwise, step 1050 follows step 1046. At step 1050another ticket blank is fed from cassette 130 or 132, as the case maybe, to refill the staging point from which the current ticket blank wasjust fed. Following step 1050 is step 1052, at which it is determinedwhether the write operation performed at step 1044 was successful. Ifnot, the routine proceeds to step 1024, described above, so that writingcan be attempted at read/write station 148. If at step 1052 the writeoperation at 1044 was found to be successful, then the routine proceedsto step 1036, also described above, for printing of the present ticketform.

Reinsertion of Old Tickets

There will now be described, with reference to FIG. 19, a procedure inwhich a ticket is reinserted into printer 44.

The procedure begins with step 1100, in which a ticket is fed intoprinter 44 via reinsertion slot 112 (FIGS. 5 and 6). The ticket may be,for example, a ticket which has just been printed but on which an errorhas been found, or may be one that a customer is returning for credit.The reinserted ticket will sometimes be referred to as the "old ticket".

Returning to FIG. 19, step 1102 follows step 1100. At step 1102, the oldticket is fed along feed path 142 past magnetic read/write station 144.Information recorded on the magnetic strip of the old ticket is thenread (step 1104). Following step 1104 is step 1106, at which it isdetermined whether the reading operation of step 1104 was successful.

If so, step 1107 follows, at which it is determined whether datarecorded on the ticket is valid (i.e. contains proper codes, has notbeen tampered with, etc.). If the ticket is valid, step 1108 follows, atwhich it determined whether an overprinting operation is to be carriedout in the old ticket. If so, new information, such as a new flightnumber and other data, a different seat number, or other data is printedon the old ticket (step 1109), assuming that there is available space onthe old ticket. Alternatively, step 1109 may include printing "VOID" ora similar legend on the old ticket. It will be understood that theoverprinting operation of step 1109 also includes recording ofappropriate data on the old ticket's magnetic stripe.

After overprinting, the old ticket is advanced to outlet 48 for ejectionfrom the printer 44 (step 1110).

Returning to step 1108, if it is determined at that step that the oldticket is not to be overprinted, step 1111 follows, during which the oldticket is fed along feed path 142 and common feed path section 146 tosecure holding bin 158 (FIG. 6).

Following step 1111 is step 1112, at which a new ticket is printed inaccordance with the procedure illustrated in FIGS. 18A-18B. Theinformation read from the old ticket's magnetic strip at step 1104 (FIG.19) is used in the magnetic recording operation with respect to the newticket carried out in accordance with step 1024 (FIG. 18B) or step 1044(FIG. 18D). Alternatively, or in addition to use of information read atstep 1104 in a magnetic recording operation (step 1024 or 1044),information read from the old ticket's magnetic strip at step 1104 maybe used in printing the new ticket as per step 1036 of FIG. 18C.Preferably the information printed and/or magnetically encoded on thenew ticket also includes new information input via a terminal 40connected to printer 44.

Again considering step 1107, if a that step the old ticket is not foundto be valid, steps 1111 and 1112, as just described, follow step 1107.

Returning now to step 1106 of FIG. 19, if it was determined at that stepthat the magnetic reading operation of step 1104 was not successful,step 1113 follows step 1106. At step 1113, it is determined whetherreading of the old ticket's magnetic strip is to be attempted again. Ifso, step 1114 follows step 1113. At step 1114 the old ticket is drivenin reverse along feed path 142 (FIG. 6), i.e. towards insertion slot112, until the old ticket is in a position between slot 112 and magneticread/write station 144. Step 1102 and so forth, as described above, thenfollow step 1114.

Returning again to step 1113, if it was determined at that step thatreading of the old ticket's magnetic strip was not to be reattempted,then step 1116 follows step 1113. At step 1116, it is determined whetherthe old ticket is to be stored in secure holding or "escrow" bin 158. Ifso, the old ticket is fed along feed paths 142 and 146 to escrow bin 158(step 1118). Otherwise, step 1120 follows step 1116. At step 1120 theold ticket is transported in a reverse direction along feed path 142towards and out of insertion slot 112.

It will be recognized that the old ticket may be inserted again intoslot 112 after it has been rejected as per step 1120. One reason whythat might be done, for example, is if the ticket was initially insertedinto slot 112 upside down, or otherwise oriented so that its magneticstripe could not be read by the magnetic read/write station. If a ticketis reinserted, the routine of FIG. 19 is again carried out.

It should also be recognized that before or instead of feeding the oldticket to the escrow bin (as in step 1118), new information can berecorded on the old ticket's magnetic stripe, either at magnetic station148, or, after reversing the old ticket, at station 144.

The above description of the invention is intended to be illustrativeand not limiting. Various changes or modifications in the embodimentsdescribed may occur to those skilled in the art and these can be madewithout departing from the spirit or scope of the invention.

What is claimed:
 1. In or for a ticket printer for printingtransportation tickets, a control system comprising:a motherboard havinga plurality of slots; control means for said printer, said control meansbeing mounted on a board plugged into one of said slots; and a pluralityof dual process personal computers, each being mounted on a board andplugged into a respective one of said slots, and each of said pluralityof dual process personal computers being connected to send data to saidcontrol means and also being adapted to perform general computing tasks.2. A control system as in claim 1 including a keyboard, disk drive, andmonitor for input/output and storage functions in connection with one ofsaid plurality of dual process personal computers.
 3. A control systemas in claim 1, wherein each of said plurality of dual process personalcomputers comprises means for selectively adapting said dual processpersonal computer for operation in one of a stand-alone mode ofoperation and a bus mode of operation.